1. Field of the Invention
The present invention relates a device and method for inducing traumatic brain injury (TBI) in animal test subjects. Specifically, the invention is (1) a device driven by compressed gases and method for launching a small projectile designed to impact a target and (2) a protective custom-designed small animal helmet that uses pressure sensor film to measure the force/distribution of the impact pressure on both the outer and inner surfaces of the helmet.
2. Brief Description of Related Art
Traumatic brain injury (TBI) has been identified as a significant public health concern affecting over 1.7 million people each year in the United States alone. The vast majority of nonfatal TBIs (75%) in military have been classified as “mild” (mTBI) typically caused by closed-head concussion (Gerberding J L and Binder S. 2003. Report to Congress on Mild Traumatic Brain Injury in the United States: Steps to Prevent a Serious Public Health Problem. In: National Center for Injury Prevention and Control, Centers for Disease Control and Prevention). Because of the high use of improvised explosive devices (IEDs) in war, there has been increased concern regarding combat-related concussions sustained by U.S. military personnel (Owens B D, Kragh J F, Jr., Wenke J C, Macaitis J, Wade C E and Holcomb J B. (2008). Combat wounds in operation Iraqi Freedom and operation Enduring Freedom. J Trauma. 64:295-299). It has been estimated that up to 28% of U.S. military personnel sustained at least one concussive mTBI event while deployed in Iraq and Afghanistan (Warden D. (2006). Military TBI during the Iraq and Afghanistan wars. J Head Trauma Rehabil. 21:398-402). Moreover, the emergence of the mTBI casualty during OIF and OEF and the extremely high incidence of which it has occurred in our soldiers has defined this combat wound as the “signature injury” of these wars. From the period 2000 through 2010, over 200,000 cases of TBI were diagnosed in the military (http://www.health.mil/Research/TBI_Numbers.aspx), with over 75% of these injuries classified as mTBI. Importantly, combat troops are often exposed to more than one concussion or mTBI in a short timeframe, the cumulative effects of which can produce long-lasting effects including physical, mental, emotional and cognitive impairments and may place our returning soldiers at increased risk for PTSD and/or neurodegenerative disorders.
Despite the high incidence of closed-head concussive mTBI in civilian and military sectors, objective diagnostic tools and knowledge about what occurs in the brain following this type of injury are limited. Ideally, the diagnosis or treatment of mTBI would be based upon understanding the injurious changes in the brain on a cellular level. However, concussive-impact induced mTBI does not produce structural changes detectable by conventional neuroimaging techniques, making clinical diagnosis challenging, particularly in the presence of more obvious injuries. Much of what has been learned about concussion in the past decade has been acquired through the systematic study of concussion sustained in sports. Currently, the clinical diagnosis of mTBI relies on symptom reporting and neurological exams, such as the Sport Concussion Assessment Tool 2 (SCAT2) National Football League (NFL) sideline exam and the Military Acute Concussion Evaluation (MACE). However, these tests typically require baseline scores for clear interpretation and rely heavily on self-reported symptoms and subjective evaluations. Increased understanding of the complex pathophysiological processes affecting the brain as a result of concussion may provide more objective diagnostic tools and improve guidelines for managing cerebral concussion for both our military population and the civilian population.
In order to study experimentally-induced concussion in animal test subjects that is clinically relevant, we have developed a device and method for producing closed-head projectile-induced concussive impact in animal test subjects. The device and method is capable of producing brain injuries ranging from mild to severe. In order to induce mild TBI, the model requires the animal test subject to wear a custom-designed small animal helmet to protect the head from bruising, yet allowing the brain to sustain an injury that meets the “clinical” criteria of a concussion.
An object of the invention is to produce an animal model with traumatic brain injury to advance research.
Another object of the invention is to inflict measured pressure wave or projectile mediated concussion in laboratory animals.
The present invention provides an experimental tool and method to elucidate the mechanism and pathology of mTBI and facilitate therapeutics research aimed specifically at mTBI treatments.